Method of moving a stack of products by use of a robot

ABSTRACT

A method moves a stack of products by a robot. The robot has an articulated arm and at least one gripper disposed on the articulated arm to grip the stack of printed products and the stack of products selectively being turned. The method includes pivoting the stack of products through an effective angle α1&lt; &gt;180° and subsequently pivoting the stack through an effective angle α2=180°−α1 or pivoting the stack back through an effective angle α2=−α1. This method of moving stacks of products is performed in an automated way and in particular of depositing them in a turned or unturned arrangement.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of copending patent application Ser.No. 17/169,786, filed Feb. 8, 2021, which claims the priority, under 35U.S.C. § 119, of German patent application DE 10 2020 103 398.2, filedFeb. 11, 2020; the prior applications are herewith incorporated byreference in their entirety.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a method that has the featuresdescribed in the preamble of the independent claim.

The technical field of the invention is the graphic industry and inparticular the field of handling (e.g. gripping, holding, moving,rotating, turning and/or depositing) stacks of products, preferablystacks of printed and folded flat products, preferably made of paper,board, metal, or a composite material, by means of a manipulator, inparticular a robot or an articulated robot.

It is known manually to transport stacks of products such as foldedsignatures from the delivery of a machine for further processing such asa folder to a pallet and to deposit them there in accordance with aknown deposit scheme. This task puts a lot of strain on the body becausefour to five stacks of products need to be moved every minute. It isalso known to use an articulated robot for this purpose, for instance aproduct called “CoBo-Stack” manufactured by MBO Maschinenbau OppenweilerBinder GmbH & Co. KG based in Oppenweiler, Germany.

In FIG. 11 a , Japanese patent application JPS6048848A disclosesgripping a stack of products at diagonally opposite corners and in FIG.9 , the document discloses a sagging of the stack. The two illustratedgrippers belong to two separate robots.

U.S. patent publication No. US 2006/263196 A1 discloses to rotate andturn a stack by means of a robot gripper.

European patent EP1645434B1, corresponding to U.S. Pat. No. 7,607,882,discloses to pivot a stack of products into an upright position and totransfer the stack of products to a clamp/to grip the stack of productsfrom above.

European patent EP2128056A1 discloses a robot with an articulated armfor handling a stack and, in FIG. 4 , a gripping device.

German utility model DE202019106975U1, corresponding to U.S. patentpublication No. 2020/0354167, discloses a handling device fortransferring a stack of products, the handling device containing agripping unit movable in three dimensions. The gripper unit containsfirst and second lateral faces and a respective upper and lower holdingelement supported for linear movement along a respective lateral face.

BRIEF SUMMARY OF THE INVENTION

An object of the present invention is to provide an improvement over theprior art in particular in such a way that stacks of products may bemoved in an automated way and deposited, in particular in a turned orunturned arrangement.

In accordance with the invention, this object is attained by the methodrecited in the independent claim.

Advantageous and thus preferred further developments of the inventionwill become apparent from the dependent claims as well as from thedescription and drawings.

The invention relates to a method of method of moving a stack ofproducts by means of a robot, the robot containing an articulated armand at least one gripper disposed on the articulated arm to grip thestack of printed products and the stack of products selectively beingturned. The invention is characterized in that the stack of products ispivoted through an effective angle α1< >180° and subsequently pivotedthrough an effective angle α2=180°−α1 or pivoted back through aneffective angle α2=−α1.

The invention advantageously provides a way of moving stacks of productsin an automated way and in particular to deposit it in a turned orunturned arrangement.

In accordance with the invention, the stack of products isadvantageously pivoted in two steps and selectively turned in theprocess. A first pivoting step is through an effective angle α1< >180°.The second step is pivoting through an effective angle α2=180°−α1. If α1and α2 both equal 90°, for example, in accordance with the invention aturn through 180° is made. If α1 and α2 are 90° and −90°, for instance,no turn is made in accordance with the invention.

The two-step pivoting process of the invention advantageously providesan opportunity to introduce intermediate steps such as vibrating orstraightening the edges of the stack of products. In addition, thetwo-step pivoting process of the invention makes it possible to carryout the two steps at different positions, for instance in that the robotcarries out a movement in between. In addition, the two-step pivotingprocess of the invention advantageously allows the two steps to becarried out by different devices, for instance the robot and a pivotingdevice that is different from the robot.

The “effective angle” is understood to indicate that the angle isindependent of the type of the pivoting movement. An effective angle of+90° may therefore be attained by a pivoting movement through +90°, twopivoting movements through +45° each, or a pivoting movement through−270°. Instead of “effective angle”, just the term “angle” may be used.

“Selectively” is understood to mean that the stack of products is eitherturned or not turned. The selection may preferably be made by a digitalcomputer, in particular as a function of what is known as a depositscheme. “Selectively” is further understood to indicate that the methodmay be carried out multiple successive times with respective stacks ofproducts and that in the process, at least one stack of products isturned and at least one stack of products is not turned.

Further Developments

The following paragraphs describe preferred further developments of theinvention (in short: further developments).

A further development may be characterized in that the pivoting throughthe effective angle α1 is achieved by a pivoting device different fromthe robot. The pivoting device may be assigned to a delivery of amachine for further processing, in particular a folder, and may inparticular be disposed thereon. It may comprise a pivotable gripper forthe stack of products. The pivoting device may be controlled by adigital computer. The pivoting device preferably pivots the stack ofproducts through α1=90°.

A further development may be characterized in that the step of pivotingthrough the effective angle α1 occurs before the step of moving, i.e. inthat the step of moving starts from the pivoted position of the stack ofproducts. The movement is preferably achieved by the robot arm.

A further development may be characterized in that the step of pivotingthrough the effective angle α1 occurs about a horizontal axis. The axismay be aligned to be parallel with the direction of transport of adelivery of a machine for further processing, in particular a folder.Before it is pivoted, the stack of products is preferably gripped andheld.

A further development may be characterized in that when the stack ofproducts is pivoted through the effective angle α1, it is pivoted out ofa horizontal position. In the horizontal position, the individualproducts, for instance folded signatures, in the stack of products arepreferably horizontal.

A further development may be characterized in that when the stack ofproducts is pivoted through the effective angle α1, it is pivoted into avertical position. In the vertical position, the individual products inthe stack of products are preferably upright.

A further development may be characterized in that the stack of productsis aligned and/or straightened in one direction and/or straightened intwo directions perpendicular to one another and/or vibrated and/oraerated when it is not in a horizontal position and/or in that afanned-out stack of products is transformed into an unfanned stack(“unfanning”). During this process, the stack of products may be in thepivoting device, e.g. in the gripper thereof. The gripper may beslightly open in particular for aeration. A straightening and/orunfanning device may comprise two vertical surfaces, for instanceplates, preferably with lateral chamfers, that are movable relative toone another. This device may be open before the pivoting step and closedafter the pivoting step. For this purpose, the surfaces may be movedtowards and away from one another. Pneumatic cylinders may be providedto create the vibration. Finally the device/the surfaces thereofpreferably move(s) into an open position so that the stack of productsmay be taken over.

A further development may be characterized in that in the verticalposition, the stack of products is turned about a vertical axis,preferably by 180°. This advantageously allows the stack of products inthe vertical position to be gripped from the same side both when it isselectively turned and when it is selectively not turned. The rotatingmay be done by the pivoting device. For this purpose, the pivotingdevice may have a rotary drive. The rotary drive may be controlled by adigital computer.

A further development may be characterized in that when the stack ofproducts is turned, it is taken over from one side of the stack ofproducts and when the stack of products is not turned, it is taken overfrom the same side of the stack of products. The takeover from the oneside or from the other side may be carried out by an articulated arm ofthe robot. The selection of the side may be computer-controlled. In thisprocess, a predefined deposit scheme may be taken into consideration.

A further development may be characterized in that the robot takes overthe stack of products in the vertical position. For this purpose, therobot and in particular the gripper thereof may be moved towards thestack of products in a computer-controlled way, for instance from aboveand/or from one side.

A further development may be characterized in that the stack of productsis moved in the vertical position, at least in a path section of themovement. The position of the stack of products may be changed along thepath of the movement, for instance by pivoting it (about a horizontalaxis) and/or by rotating it (about a vertical axis).

A further development may be characterized in that the robot takes overthe stack of products from the pivoting device and then moves it. Thestack of products may be taken over and held by a gripping device of therobot. The movement may be effected by moving an articulated arm of therobot. The robot may additionally be displaced in a horizontaldirection. All actions of the robot may preferably becomputer-controlled.

A further development may be characterized in that when the stack isturned, it is taken over from one side of the stack of products and whenthe stack is not turned, it is taken over from the opposite side of thestack of products. The takeover from the one side or from the other sidemay be carried out by an articulated arm of the robot. In this process,a gripping device of the robot may be rotated in such a way that agripping action occurs from the one side or from the other side. Theselection of the side may be computer-controlled. In this process, apredefined deposit scheme may be taken into consideration.

A further development may be characterized in that the pivoting throughthe effective angle α2 occurs during the movement or in between twomovement portions or after the movement. The pivoting movement may becomputer-controlled. In this process, a predefined deposit scheme may betaken into consideration.

A further development may be characterized in that the pivoting throughthe effective angle α2 is done using the robot. The pivoting movementmay be achieved by a corresponding movement of an articulated arm of therobot and/or by a pivoting device on the robot/on the articulated armthereof and/or by a pivotable gripping device on the robot/thearticulated arm thereof. The pivoting movement may becomputer-controlled.

A further development may be characterized in that as the stack ofproducts is pivoted through the effective angle α2, it is pivoted backinto a horizontal position. In this case, the stack of products is notturned, i.e. it is deposited unturned.

A further development may be characterized in that the stack of productsis deposited in the horizontal position. The stack is preferablydeposited on a pallet. To deposit the stack, grippers on the robot maysimultaneously or successively be opened and moved away laterally.

A further development may be characterized in that before the stack ofproducts is deposited, it is rotated about a vertical axis. This allowsthe alignment of the stack of products in the horizontal to be modified,for instance effectively by 90° or 180°. The rotation may becomputer-controlled. In this process, a predefined deposit scheme may betaken into consideration.

A further development may be characterized in that the effective angleα1 equals 90° and the effective angle α2 equals 90° and in that thestack is pivoted further through α2. When the stack is pivoted further,the pivoting movement through al and the pivoting movement through α2preferably occur in the same pivoting direction. In this process, thetotal effect is that the stack of products is turned.

A further development may be characterized in that the effective angleα1 equals 90° and the effective angle α2 equals −90° and that the stackis pivoted back through α2. When the stack is pivoted back, the pivotingmovement through al and the pivoting movement through α2 preferablyoccur in opposite pivoting directions. In this process, the total effectis that the stack of products is not turned.

A further development may be characterized in that the stack of productsis held by at least two grippers during the movement.

A further development may be characterized in that the stack of productsis held in a form-fitting/positive and/or force-fitting/non-positive wayduring the movement.

A further development may be characterized in that one side of the stackof products has at least four corners and in that the stack of productsis held at diagonally opposite corners during the movement. If there aremore than four corners, edges may be selected that are spaced apart by alarge distance and/or are spaced apart in a way that is a goodapproximation to being diagonally opposite each other.

A further development may be characterized in that selectively, twodiagonally opposite corners or two other diagonally opposite corners maybe held. The selection of the corners may be computer-controlled. Inthis process, a predefined deposit scheme may be taken intoconsideration. For this purpose, a gripping device on the robot arm ispreferably rotated.

A further development may be characterized in that the stack of productsis held in such a way that the stack of products sags. For this purpose,the distance between grippers of the robot may be reduced preferably ina computer-controlled way until a desired or predefined sag is attained.The stack of products may be formed of folded paper sheets.

A further development may be characterized in that the stack of productsis held in such a way that the stack of products sags diagonally. Inthis way, the stack of products with the diagonal as its “lowest point”may be deposited in a controlled and self-fixing way. For this purpose,the stack of products may be held on diagonally opposite corners.

Special Further Developments Pertaining to Stack Deposition

The following paragraphs describe preferred further developments of theinvention (in short: further developments).

A further development may be characterized in that the movementterminates at a selected deposit position among multiple depositpositions of a predefined deposit scheme. The deposit scheme may besaved on a digital computer or on a network connected thereto. Aplurality of deposit schemes may be saved, for instance in a database.The selection of the deposit position (and/or a sequence of depositpositions for stack of products to be moved in succession) may becomputer-controlled. When a transport stack is built up out of stacks ofproducts, a deposit scheme may be selected for every horizontal layer,in particular different deposit schemes may be selected for twosuccessive layers.

A further development may be characterized in that the stack of productsis deposited at the selected deposit position on a base, preferably apallet.

A further development may be characterized in that the stack of productsis held in such a way that it sags in the diagonal and in that when thediagonally-sagging stack of products is deposited, the sagging portionis the first to touch the base.

A further development may be characterized in that the deposit scheme issaved on a digital computer or uploaded onto the digital computer fromanother digital computer via a network and in that the movement iscontrolled by the digital computer.

A further development may be characterized in that the deposit scheme iscalculated and/or selected by the digital computer as a function of atleast one of the following parameters: dimensions of the stack ofproducts; dimensions of the base; in a case in which the stack ofproducts is a stack of folded products: position of the folding edgesrelative to the base and/or structure of the folding edges as a functionof the type of fold.

A further development may be characterized in that multiple stacks ofproducts are successively moved, selectively turned, selectively rotatedin the horizontal, and deposited at respective selected depositpositions among multiple deposit positions of the predefined depositscheme. In this process, a computer-controlled robot with an articulatedarm and a gripping device may be used.

Special Further Developments Pertaining to the Gripping Operation

The following paragraphs describe preferred further developments of theinvention (in short: further developments).

A further development may be characterized in that two grippers are usedand in that when the stack of products is deposited, the grippers aremoved away from the stack of products in the horizontal in twodirections perpendicular to one another.

A further development may be characterized in that when the stack ofproducts is deposited, the grippers open in the vertical. In thisprocess, a gripper jaw of the gripper may be moved; preferably, agripper jaw located above the stack of products may be moved upward. Theother gripper jaw, preferably the one underneath the stack of products,may be unmoved.

A further development may be characterized in that every stack ofproducts is moved to a respective deposit position of the depositscheme, the respective deposit position selected in such a way that inthe deposit position, the grippers are removed from the stack ofproducts in the horizontal and without collision with stacks of productsthat have already been deposited.

Further Developments

The following paragraphs describe preferred further developments of theinvention (in short: further developments).

A further development may be characterized in that the movement of thestack of products occurs from a delivery of a machine for the furtherprocessing of printed products to a pallet or to one of several pallets.In the latter case, non-stop operation is possible.

A further development may be characterized in that the movement of thestack of products occurs from a delivery of a machine for the furtherprocessing of printed products, for instance a folder, a saddlestitcher, or a perfect binder, to a pallet or to one of several pallets.

A further development may be characterized in that the stacks ofproducts are transported in a direction of transport in the delivery andare separated from one another in the direction of transport. Thetransport may occur on a roller-type conveyor. For the separation,individual drivable rollers may be driven or stopped in an appropriateway.

A further development may be characterized in that the robot is movableand usable at multiple positions of a machine for further processing orat multiple machines for further processing. For this purpose, the robotmay be supported on rollers and/or rails.

A further development may be characterized in that the stack of productsis formed of folded and/or die-cut printed products.

A further development may be characterized in that multiple stacks ofproducts are stacked on top of one another to be horizontally offsetrelative to one another and in multiple horizontal planes above oneanother to form a transport stack on a transport pallet or in that atransport stack is formed or built up in a corresponding way. Theselection of the offset and/or of the planes may be computer-controlled.In this process, a predefined deposit scheme may be taken intoconsideration.

A further development may be characterized in that a sensor disposed onthe robot detects the height of the transport stack. The sensor may bedisposed on a gripping device of the robot. Multiple sensors may beprovided. The height may be determined in absolute terms, for instancemeasured from the upper edge of a pallet or floor, or in relative termsas a distance to the sensor.

A further development may be characterized in that the height isdetected as a single height value, as a number of height values atvarious horizontal positions, or as a height profile.

A further development may be characterized in that as the sensor, adistance sensor for measuring the height is used or in that a camerawith digital image processing to calculate the height on the basis ofthe camera image is used.

A further development may be characterized in that the robot arm ismoved without collision over a transport stack that has only partly beenbuilt up and in that the digital computer factors in the detected heightas it controls the movement of the robot arm.

A further development may be characterized in that the robot takesindividual intermediate layers off of a stack and deposits them onrespective planes. The intermediate layers may be made of cardboard. Thedeposit of intermediate layers may be computer-controlled. In thisprocess, a predefined deposit scheme and/or stacking scheme may be takeninto consideration.

A further development may be characterized in that the intermediatelayer is held by suction. For this purpose, a suction gripper may bedisposed on a gripping device of the robot. A number of such suctiongrippers may be used.

A further development may be characterized in that the movement is donein a fully automated way, as a function of a selected deposit schemeand/or stacking scheme and in a way adapted to the production speed ofthe at least one machine for further processing.

A further development may be characterized in that the movement of therobot arm occurs in a protected area.

A further development may be characterized in that to create theprotected area, a housing and/or a fence and/or a light barrier and/or amonitoring camera is used.

Special Further Developments Pertaining to a Device for Implementing theMethod

The following paragraphs describe preferred further developments of theinvention (in short: further developments).

A further development of the method of the invention may becharacterized by the use of a device with a robot for moving a stack ofproducts, the robot containing an articulated arm and a first gripperfor the stack of products disposed on the articulated arm. The method ischaracterized in that a gripping device containing the first gripper anda second gripper is disposed on the articulated arm, the first gripperand the second gripper being positioned relative to one another.

The aforementioned device as such may represent a further invention.

A device for moving a stack of products with a robot, the robotcontaining an articulated arm and a first gripper for the stack ofproducts disposed on the articulated arm. The device is characterized inthat a gripping device comprising the first gripper and a second gripperis disposed on the articulated arm, the first gripper and the secondgripper being positionable relative to one another.

The device as such or the use thereof advantageously provides a way ofmoving stacks of products in an automated way, in particular to depositthem in a turned or unturned arrangement.

A particular advantage may be considered to be that stacks of productsof different sizes or formats may be moved and in particular selectivelydeposited in a turned or unturned arrangement.

The following paragraphs describe preferred further developments of theinvention (in short: further developments). These further developmentsmay also represent preferred further developments of the furtherinvention, i.e. the device as such.

A further development may be characterized in that the two grippers arepositionable, preferably in a computer-controlled way, to accommodatepredefined formats of products or stacks of products. The grippers maybe movable, preferably linearly movable, for positioning purposes. Thepositioning is preferably computer-controlled.

A further development may be characterized in that the two grippers arepositionable on the two ends of a selected diagonal of a selectedformat. The positioning is preferably computer-controlled.

A further development may be characterized in that the first gripper isconfigured as a first pliers-type gripper with a first pair of gripperjaws and the second gripper is designed as a second pliers-type gripperwith a second pair of gripper jaws.

A further development may be characterized in that each one of the twopairs of gripper jaws contains an immobile gripper jaw and a mobilegripper jaw that is linearly movable relative to the immobile gripperjaw. Linear drives may be provided, preferably electric linear driveswith threaded spindles. Of course, the immobile gripper jaws are nottotally immobile: they may be moved by the motion of the robot, of thegripping device and/or of the grippers. The immobile gripper jaws areonly unmoved or only negligibly moved relative to the movable gripperjaws when the grippers open and close.

A further development may be characterized in that each one of theimmobile gripper jaws comprises a support element extending in ahorizontal direction and at least one stop element extending in avertical direction.

A further development may be characterized in that each one of theimmobile gripper jaws contains a support pad extending in a horizontaldirection as the support element and two stop surfaces extending in avertical direction and perpendicular to one another as stop elements.All surfaces may be perpendicular to one another.

A further development may be characterized in that the stack of productsis held in a form-fitting/positive and/or friction-fitting/non-positiveway during the movement.

A further development may be characterized in that at least one blowerdevice is disposed on the gripping device to blow air under the stack ofproducts when the stack of products is deposited.

A further development may be characterized in that at least one furthergripper is disposed on the gripping device, the further gripper designedas a suction gripper for intermediate layers. For suction-based grippingand holding, suction air may be applied to the suction gripper in acomputer-controlled way.

A further development may be characterized in that at least one distancesensor and/or at least one camera is provided on the gripping device.

A further development may be characterized in that the gripping devicecontains a first support arm on which the first gripper is disposed forlinear movement in the longitudinal direction of the first support arm.

A further development may be characterized in that the gripping devicecontains a second support arm on which the second gripper is disposedfor linear movement in the longitudinal direction of the second supportarm.

A linear drive, preferably an electric linear drive with a threadedspindle, may be provided on the support arm to move the grippers alongthe support arms. The linear drive may be electric. The support arm mayhave a length correlating with a maximum-format stack of products to bemoved.

A further development may be characterized in that the first support armand the second support arm are disposed on the gripping device so as tobe perpendicular to one another. The support arms may form an X-Y axissystem for format-adjustable grippers. Movable gripper jaws of thegrippers may form the Z axis that is perpendicular thereto.

A further development may be characterized in that the two linearlymovable gripper jaws are movable in a direction perpendicular to therespective support arm.

A further development may be characterized in that the gripping deviceis disposed on the robot arm so as to be rotatable about an axis ofrotation. The axis of rotation is preferably for rotating the stack ofproducts about a vertical axis and/or for depositing a stack of productsthat has been rotated in the horizontal.

A further development may be characterized in that the gripping deviceis disposed on the robot arm so as to be pivotable about a pivot axisperpendicular to the axis of rotation. The pivot axis is preferably forpivoting the stack of products about a horizontal axis and/or fordepositing a stack of products that has selectively been turned or notturned relative to the horizontal.

A further development may be characterized in that the articulated armhas six axes, preferably axes of rotation.

A further development may be characterized in that the robot ishorizontally displaceable, for instance on rails or rollers, relative toone or more machines for further processing that create stacks ofproducts.

In any desired combination with one another, the features andcombinations of features described in the above sections TechnicalField, Invention, and in the various sections above on furtherdevelopments as well as in the following section Exemplary Embodimentsrepresent further advantageous further developments of the invention.

As an alternative to the aforementioned 2-step pivoting process, theobject may be attained by a single-step pivoting process. In thisprocess, for selective turning, the stack of products in horizontalalignment is preferably gripped from below by the gripping device of anarticulated robot and pivoted through an effective angle of 180°, forinstance while it is being moved to the pallet. When the stack is not tobe turned, the stack of products in horizontal alignment may preferablybe gripped from above.

Other features which are considered as characteristic for the inventionare set forth in the appended claims.

Although the invention is illustrated and described herein as embodiedin a method of moving a stack of products by means of a robot, it isnevertheless not intended to be limited to the details shown, sincevarious modifications and structural changes may be made therein withoutdeparting from the spirit of the invention and within the scope andrange of equivalents of the claims.

The construction and method of operation of the invention, however,together with additional objects and advantages thereof will be bestunderstood from the following description of specific embodiments whenread in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 is an illustration of a preferred exemplary embodiment of adevice containing a robot for carrying out steps of a preferredembodiment of a method according to the invention;

FIG. 2 is a perspective view of a delivery of a machine for furtherprocessing;

FIGS. 3A and 3B are perspective views of preferred exemplary embodimentsof the delivery;

FIGS. 4A to 4D are perspective views of preferred exemplary embodimentsof a robot-guided gripping device;

FIG. 5 is a perspective view of a preferred exemplary embodiment of thegripping device;

FIGS. 6A and 6B illustrate preferred exemplary embodiments of depositschemes;

FIG. 7 is a lateral view of a preferred exemplary embodiment of atransport stack; and

FIG. 8 is a flow chart for illustrating a method for moving a stack ofproducts by means of a robot.

DETAILED DESCRIPTION OF THE INVENTION

In the drawings, corresponding features have the same reference symbols.Repetitive reference symbols have sometimes been left out for reasons ofvisibility. The following is a summary list of reference numerals andthe corresponding structure used in the above description of theinvention.

Referring now to the figures of the drawings in detail and first,particularly to FIG. 1 thereof, there is shown a preferred exemplaryembodiment of a device preferably containing a robot and carrying outsteps of a preferred embodiment of the method of the invention. FIG. 1is a view from above.

A machine 70 for further processing, preferably a folder, which is onlypartly shown, is located in a position 74 and produces printed products2, preferably printed and/or folded signatures 2, which are in the formof stacks 1 of products and are moved, e.g. conveyed, in a direction oftransport 71 on a delivery 72. The action of the delivery, in particularthe conveying action, may be controlled by a digital computer 80. Astack of products preferably contains a plurality of products resting ontop of one another.

The digital computer 80, which is preferably connected to a network 81,may control the machine 70 for further processing and optionally furthermachinery; for instance, it may provide job data for the manufacturingof products. Job data may be provided via the network.

The delivery 72 may move the stacks 1 of products into a protected zone73. A robot 10, preferably a robot containing an articulated arm 11 withmultiple axes 12, for instance six axes, may be disposed in this zone.The robot may be a common industrial robot.

A gripping device 20 is disposed on the robot 10, preferably at the endof the articulated arm/“hand” 11 thereof. The gripping device may gripand hold stacks 1 of products to move them away from the delivery 72,preferably only within the protected zone. The movement 15 moves thestack 1 of products along a spatial curve to a transport pallet 62,where the stack of products is deposited and preferably positioned at adeposit location 60 in accordance with a deposit scheme 61. A number ofpallets may preferably be provided within reach of the robot. Themovement may comprise multiple movement portions 16. In between twomovement portions, the gripping device may be rotated and/or pivoted,for instance. The rotating and/or pivoting may likewise occur during themovement.

A pivoting device 40 is preferably disposed at the end of the delivery72. The pivoting device 40 may pivot the stacks 1 of products out of thehorizontal 50, horizontal plane 53 or the horizontal position 52 intothe vertical 54, the vertical plane 57 or the vertical position 56,respectively. The pivoting device may comprise two alignment elements41, which are preferably movable in a horizontal direction, and/orstraightening elements 42 for the stack of products. They may beembodied as surfaces, for instance plates.

The action, in particular the movement 15 and/or 16 of the robot 10,and/or the action, in particular the pivoting, of the pivoting devicemay be controlled by the digital computer 80.

FIG. 2 illustrates a preferred exemplary embodiment of a delivery of amachine for further processing. The delivery 72 may contain a pluralityof rollers 76. The delivery may be a roller conveyor. Some of therollers may be driven, for instance by motors 75. The digital computer80 may control the process of conveying the stacks 1 of products 2resting on top of one another. In this process, the stacks of productsmay be separated from one another in the direction of transport 71. Theproducts 2 and therefore also the stacks 1 of products that have beenformed preferably have four corners 5. Die-cut products may have morecorners. If the products are folded products, their folding spines arepreferably oriented to be parallel to the direction of transport.

FIGS. 3A and 3B illustrate preferred exemplary embodiments of thedelivery, preferably containing the pivoting device, as they carry outsteps of a preferred embodiment of the method of the invention. FIGS. 3Aand 3B are perspective views.

FIGS. 3A and 3B illustrate the end of the folder 70 and the delivery 72on which the stacks 1 of products are conveyed in the direction 71 oftransport up to a pivoting device 40 (transporting step 101). Beforebeing pivoted, the stacks of products and consequently the products 2are preferably in a horizontal position 52.

The pivoting device 40 preferably contains grippers 43, for instancebars movable relative to one another, preferably one bar (closing“hold-down element”) on one side of the stack 1 of products and threebars on the other side of the latter. The pivoting device and/or thegrippers thereof may be pivoted about a horizontal axis 51. Thegrippers, which are located below the stack 1 of products in FIG. 3A,may be positioned between the rollers 76 and may be pivoted out of thisposition.

FIGS. 3A and 3B illustrate sections of the robot 10 and the articulatedarm 11 thereof. The robot is preferably movable in a horizontaldirection on the floor and therefore positionable at various locations.The robot may, for instance, be supported on rollers. For example, railsmay be provided.

FIGS. 3A and 3B illustrate the—preferably horizontally movable—alignmentelements 41 and/or straightening elements 42.

A comparison between FIGS. 3A and 3B illustrates the pivotingmovement/pivoting 110 through an effective angle α1 (pivoting step 110).In the illustrated example, the angle α1 is preferably 90°. After thepivoting step, the stack 1 of products is preferably in a verticalposition 56. If the products 2 are folded products, in the verticalposition, the spines are preferably at the top.

FIGS. 3A and 3B illustrate two sides 3 and 4. The robot 10 maypreferably grip the pivoted stack 1 of products from side 3 or fromopposite side 4. Side 3 may be referred to as the front side and side 4as the back side. The selection of the side may be computer-controlledas a function of a deposit scheme.

The pivoting device may optionally be configured for rotation and maythus be rotated about a vertical axis 55. The stack of products maypreferably be rotated through 180°. In accordance with this option, therobot 10 may always grip the pivoted stack 1 of products from the sameside, preferably from side 3/the front side.

FIGS. 4A to 4D illustrate preferred exemplary embodiments of arobot-guided gripping device as it carries out steps of a preferredembodiment of the method of the invention. The figures are perspectiveviews.

FIGS. 4A to 4D illustrate a flange 26 of the robot 10. A gripping device20 for stacks 1 of products is preferably disposed on the flange. Thegripping device is preferably disposed for rotation about an axis ofrotation 13 (rotating step 142). The gripping device is pivotable abouta pivoting axis 14 (further pivoting step 122 or back pivoting step123). Both the axis of rotation and the pivoting axis may be arespective single axis 12 of the robot or respective multiple axes.

The gripping device 20 preferably contains two support arms: a firstsupport arm 21 and a second support arm 23. The support arms arepreferably perpendicular to one another. A first gripper 30 ispreferably disposed on the first support arm so as to be movable in afirst longitudinal direction 22. A second gripper 32 is preferablydisposed on the second arm so as to be movable in a second longitudinaldirection 24. The grippers may be driven by linear drives 25 to beadjusted as a function of the format.

The first gripper 30 preferably contains a first pair of gripper jaws 31including an immobile gripper jaw 31 a and a movable gripper jaw 31 b.The movable gripper jaw may be driven by a linear drive 37. The secondgripper 32 preferably contains a second pair of gripper jaws 33including an immobile gripper jaw 33 a and a movable gripper jaw 33 b.The movable gripper jaw may be driven by a linear drive 37. Each one ofthe immobile gripper jaws may include a support element 34, preferably asupport surface. The movable gripper jaws act to open and close thegrippers.

The grippers 30 and a 32 grip the stack 1 of products 2 preferably atthe corners 5 thereof and especially at corners 6 that are diagonallyopposite one another (see diagonal 7 in FIG. 5 ).

In the example illustrated in FIG. 4A, the gripping device 20 grips thestack 1 of products that has been pivoted into a vertical position fromside 4, i.e. from the back side, for instance. In other words, when thegripping device grips the stack of products, it is preferably located onside 4. To illustrate this, the transport direction 71 is indicated.

In the example illustrated in FIG. 4B, the gripping device 20 likewisegrips the stack 1 of products that has been pivoted into a verticalposition from side 4, i.e. from the back side, for instance.

A comparison between FIGS. 4A and 4B shows that either the first pair ofcorners 5 (top left and bottom right) or the other pair of corners 5(bottom left and top right) may be gripped. The edges may be selected ina computer-controlled way and as a function of a deposit scheme.

In the example shown in FIG. 4C, the gripping device 20 grips the stack1 of products that has been pivoted into the vertical from side 3, i.e.from the front side, for instance.

In the example shown in FIG. 4D, the gripping device 20 grips the stack1 of products that has been pivoted into the vertical from side 3, i.e.from the front side, for instance.

A comparison between FIGS. 4C and 4D in turn shows that either the onepair of corners 5 (“top left” and “bottom right”) or the other pair ofcorners 5 (“bottom left” and “top right”) may be gripped. The edges mayagain be selected in a computer-controlled way and as a function of adeposit scheme.

The decision whether the stack 1 of products is gripped from side 3 orfrom side 4 and whether the one pair of corners 5 or the other pair ofcorners 5 is gripped in this process depends on how the stack ofproducts is to be deposited—whether it is to be deposited in a turned orunturned arrangement and whether it is to be deposited in a rotated orunrotated arrangement. This in turn depends on a selected deposit schemeand the respective deposit position within this scheme. The digitalcomputer 80 controls the gripping operation and the appropriate actionof the robot 10 in accordance with the deposit scheme and depositposition. In this process, the side and the corners are selectedaccordingly.

Having been gripped and during the movement 130, in particular inbetween two movement portions 130 a and 130 b and preferably beforebeing deposited (step 152), the stack 1 of products is pivoted througheffective angle α2—either pivoted further (step 122) or pivoted back(step 123). When it is pivoted further, the stack of products ispreferably deposited in a turned arrangement (turning step 140); when itis pivoted back, it is deposited in an unturned arrangement (non-turningstep 141).

FIG. 5 illustrates a preferred exemplary embodiment of the grippingdevice as it carries out step 150 of letting a stack of products sag inaccordance with a preferred embodiment of the method of the invention.FIG. 5 is a perspective view.

FIG. 5 shows the gripping device 20 with the two grippers 30 and 32. Thegrippers hold a stack 1 of products at diagonally opposite corners 6.The grippers are positioned/spaced apart from one another on the twosupport arms 21 and 23 as a function of the format of the stack ofproducts and in such a way that the stack of products sags (step 150 ofletting the stack sag). When the stack of products is deposited on thetransport pallet 62 or on a transport stack 64 that has already beenformed, the sagging diagonal 8 touches the pallet/the transport stackfirst. This allows the stack of products to be deposited in a preciseway without disturbance and the open grippers 30 and 32 to be moved awayfrom the stack of products by moving them in directions 58 perpendicularto one another. The digital computer 80 may control the opening andmoving away.

FIG. 5 illustrates the two immobile gripper jaws 31 a and 33 a with tworespective stop elements 35, in particular stop surfaces 35. When thestack 1 of products is deposited, the two support elements 34 (disposedbelow the stack of products and therefore not visible in FIG. 5 ) arepreferably oriented in a horizontal direction, whereas the tworespective (i.e. four) stop elements are preferably oriented in avertical direction. The opening and closing of the grippers/the movementof the movable gripper jaws 31 b and 33 b occurs in a direction 38.

FIG. 5 illustrates a sensor 66, preferably disposed on one of theimmobile (“lower”) gripper jaws 31 a or 33 a. The sensor may measure thedistance to the pallet or to the transport stack that has already beenformed or the height 65 and may transmit the measured value to thedigital computer 80, allowing the latter to control a precise and inparticular collision-free deposit.

FIG. 5 illustrates two further grippers 36, in particular suctiongripper 36. They are preferably used to grip and hold intermediatelayers 67.

FIGS. 6A and 6B illustrate preferred exemplary embodiments of depositschemes.

FIGS. 6A and 6B are top views of an example of twelve stacks 1 ofproducts. They were deposited in an order from stack 1 to stack 12.

At a respective corner of every stack of products, the gripping device20 and flange 26 are shown as a circle. At two respective corners, thetwo grippers 30 and 32 are shown. Each one of arrows 58 indicates thedirections into which the opened grippers are moved to release the stackof products.

Depositing the stacks 1 of products at the deposit positions 60 inaccordance with the respective selected deposit scheme 61 allows thegrippers 30 and 32 to move in the horizontal without colliding withstacks of products that have already been deposited before.

As shown in FIGS. 6A and 6B, what is referred to as a “chimney” 68, anempty space in the deposit scheme, may be created.

A comparison between FIGS. 6A and 6B shows that the deposit scheme maychange. The deposit scheme is preferably changed in every new horizontalplane/layer of a transport stack to be formed. This improves thestability of the transport stack.

FIG. 7 illustrates a preferred exemplary embodiment of a transport stackcreated by the steps of “depositing”. FIG. 7 is a lateral view.

A first layer 63 of stacks 1 of products has been deposited on atransport pallet 62 in accordance with a first deposit scheme. On top ofit, an intermediate layer 67 has been deposited. The robot may takeintermediate layers off a neighboring stack of intermediate layers.Suction grippers 36 may be used for this purpose. A second layer 63 ofstacks 1 of products is deposited on the intermediate layer inaccordance with the second deposit scheme, which is preferably differentfrom the first deposit scheme. As it can be seen, the edges of thestacks 1 of products may have a horizontal offset 69 relative to oneanother. This improves the stability of the transport stack.

As the gripping device 20 approaches the transport stack 64, the sensor66 may measure the vertical distance 65 and the digital computer 80 mayuse the measured value to control the collision-free movement of thegripping device.

FIG. 8 illustrates a preferred exemplary embodiment of a flow chart.Optional steps are indicated by dashed lines.

The processing step (100) may comprise the manufacturing of foldedproducts 2.

The transporting step (101) may comprise the transportation of stacks 1of products into a direction of transport 71.

The separating step (102) may comprise the separation of stacks 1 ofproducts in the direction of transport 71.

The stopping step (103) may comprise the stopping of the stack 1 ofproducts at a pivoting device 40.

The pivoting step (110) may comprise a pivoting of the stack 1 ofproducts 1 by means of a pivoting device 40, in particular through anangle α1=90°.

The aligning step (111) may comprise an alignment of the stack ofproducts, preferably about a vertical axis. Alignment elements 41 may beused for this purpose.

The step of straightening (112) may comprise a straightening of theproducts 2. A straightening element 42 may be used for this purpose.

The vibrating step (113) may comprise a vibration of the stack 1 andconsequently of the products 2.

The aerating step (114) may comprise an aeration of the stack 1 ofproducts. The aeration may be attained by the vibration.

The modifying step (115) may transform a fanned-out stack of products 1into an unfanned stack of products. Alignment elements 41 may be usedfor this purpose. Each one of them may be formed by a surface such as aplate with two chamfers.

The takeover step (120) may be done by the gripping device 20 and inparticular the grippers 30 and 32 thereof. In the takeover, the stack ofproducts may be transferred from the pivoting device 40 to the grippingdevice 20. The takeover may occur from side 3 or from side 4.

The holding step (121) may be done by the closed grippers 30 and 32.

The forward pivoting step (122) may be done by the robot arm 11, inparticular through α2=90°.

The back pivoting step (123) may be done by the robot arm 11, inparticular through α2=−90°. Further pivoting or back pivoting arepreferably selected as a function of the deposit scheme.

The moving step/movement (130) is preferably done using the robot 10.

The partial moving step/movement portion (130 a) and the partialmoving/movement portion (130 b) are preferably done using the robot 10.

The calculating step (131) is preferably done using the digital computer80. The movement of the robot 10 may be calculated.

The controlling step (132) is preferably done using the digital computer80. The movement of the robot 10 may be calculated.

The turning step (140) may be done by the robot arm 11, in particularthrough α1+α2=180°.

The non-turning step (141) may be done by the robot arm 11, inparticular through α1+α2=0°.

The rotating step (142) may be done by the robot arm 11.

The step of letting sag (150) may be attained due to an adjustabledistance between the two grippers 30 and 32.

The measuring step (151) of measuring the distance 65 and/or height 65may be done by the sensor 66.

The depositing/stacking step (152) may be done by the robot arm 11. Inthis process, a predefined deposit scheme 61 may in particular be takeninto consideration.

The following is a list of reference numerals and symbols appearing inthe foregoing description with reference to the figures of the drawing:

-   1 stack of products-   2 printed products, in particular folded printed products-   3 side-   4 opposite side-   5 corners-   6 diagonally opposite corners-   7 diagonal-   8 sagging diagonal-   10 device, in particular robot-   11 robot arm/articulated arm-   12 axes-   13 axis of rotation-   14 pivot axis-   15 movement/path-   16 part of movement/part of path-   20 gripping device-   21 first support arm-   22 first longitudinal direction-   23 second support arm-   24 second longitudinal direction-   25 linear drive-   26 flange-   30 first gripper, in particular pliers-type gripper-   31 first pair of gripper jaws-   31 a immobile gripper jaw-   31 b mobile gripper jaw-   32 second gripper, in particular pliers-type gripper-   33 second pair of gripper jaws-   33 a immobile gripper jaw-   33 b mobile gripper jaw-   34 support element, in particular support pad-   35 stop elements, in particular two stop surfaces-   36 further gripper, in particular suction gripper-   37 linear drive-   38 movement to open/close the grippers-   39 blower device-   40 pivoting device-   41 alignment elements-   42 straightening element-   43 gripper-   50 horizontal-   51 horizontal axis-   52 horizontal position-   53 horizontal plane-   54 vertical-   55 vertical axis-   56 vertical position-   57 vertical plane-   58 two directions perpendicular to one another-   60 deposit position-   61 deposit scheme-   62 base, in particular pallet-   63 position of already deposited stacks of products-   64 transport stack-   65 height-   66 sensor, in particular distance sensor or camera-   67 intermediate layer-   68 chimney-   69 offset-   70 machine for further processing, in particular folder-   71 direction of transport-   72 delivery-   73 protected zone-   74 position of a machine for further processing-   75 drives-   76 rollers-   80 digital computer-   81 network-   100 processing step-   101 transporting step-   102 separating step-   103 stopping step-   110 pivoting step-   111 aligning step-   112 straightening step-   113 vibrating step-   114 aerating step-   115 changing step-   120 takeover step-   121 holding step-   122 step of further pivoting-   123 step pivoting back-   130 moving step/movement-   130 a partly moving step/movement portion-   130 b partly moving step/movement portion-   131 calculating step-   132 controlling step-   140 turning step-   141 step of not turning-   142 rotating step-   150 step of letting sag-   151 measuring step-   152 depositing/stacking step-   α1 (first) effective angle-   α2 (second) effective angle

1. A method of moving a stack of products by a robot, the robotcontaining an articulated arm and at least one gripper disposed on thearticulated arm to grip the stack of products, the method comprising:pivoting the stack of products through an effective angle α1=90° into avertical position; subsequently pivoting the stack through an effectiveangle α2=90° or pivoting the stack back through an effective angleα2=−90°; and selectively turning the stack in the vertical positionabout the vertical axis by the pivoting device.
 2. The method accordingto claim 1, wherein the step of pivoting through the effective angle α1is done using a pivoting device different from the robot.
 3. The methodaccording to claim 1, wherein the step of pivoting through the effectiveangle α1 occurs before a step of moving.
 4. The method according toclaim 1, which further comprises, subsequent to pivoting the stackthrough the effective angle α1 and prior to pivoting the stack throughthe effective angle α2, subjecting the stack to at least one processstep selected from the group consisting of aligning the stack,straightening the stack, vibrating the stack, aerating the stack, andmodifying the stack.
 5. The method according to claim 1, wherein thestack of products is not in a horizontal position when it is alignedand/or straightened in a direction and/or straightened in two directionsperpendicular to one another and/or vibrated and/or aerated and/orwherein a fanned-out stack of products is modified to become an unfannedstack of products.
 6. The method according to claim 2, which furthercomprises taking over the stack of products from the pivoting device bythe robot and then moving the stack of products.
 7. The method accordingto claim 1, wherein the step of pivoting through the effective angle α2occurs during a step of moving or between two movement portions or afterthe step of moving.
 8. The method according to claim 1, wherein the stepof pivoting through the effective angle α2 is done using the robot. 9.The method according to claim 1, wherein a side of the stack of productshas at least four corners, and wherein during a step of moving, thestack of products is held at diagonally opposite corners.
 10. The methodaccording to claim 1, which comprises holding the stack of products insuch a way that the stack of products sags in a diagonal direction. 11.The method according to claim 1, wherein a step of moving the stack ofproducts includes moving the stack from a delivery of a machine forfurther processing of printed products to a pallet or to one of aplurality of pallets.
 12. The method according to claim 1, which furthercomprises stacking multiple stacks of products on top of one another soas to be horizontally offset with one another and in multiple horizontalplanes above one another to form a transport stack on a transportpallet.
 13. The method according to claim 12, which comprises detectinga height of the transport stack by a sensor disposed on the robot. 14.The method according to claim 13, wherein the step of detecting theheight comprises detecting the height as one of a single height value, anumber of height values at different horizontal positions, of a heightprofile.
 15. The method according to claim 14, wherein the articulatedarm is moved without collision over the transport stack that has onlypartly been formed, and wherein a digital computer factors in a detectedheight as it controls a movement of the articulated arm.
 16. The methodaccording to claim 1, wherein a step of moving is done in a fullyautomated way in dependence on a selected deposit scheme and is adaptedto a production speed of at least one machine for further processing.17. The method according to claim 1, which comprises moving the robotarm within a protected zone.